Harvesting aniseed

I have been growing Pimpinella anisum from seed, and the plants have flowered on my window sill; most are now going to seed and the flower heads are fading. I hear I can store the seed by snipping off the flower heads to keep in a dark drawer, and that this is how to harvest aniseed for culinary use. Is it and, if so, how exactly should I go about it? Thanks.